Increase the number of shards for some tests

This is to make CQ check faster when update clang like below.
https://chromium-review.googlesource.com/c/chromium/src/+/1143094

This CL increases the number of shards so that max shard duration reduced around 30 minutes.

I use shard duration of following builds to adjust the number of shards.
* https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_chromium_chromeos_asan_rel_ng/15713
* https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_chromium_chromeos_msan_rel_ng/831

Bug: 794372, 865455
Change-Id: Iee4e55af62219ba6d4f36d3ff5bcf53e5b7e9725
Reviewed-on: https://chromium-review.googlesource.com/1143435
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576584}
2 files changed